Corrosion inhibitor compositions containing nitrite and/or nitrate salts are well known. While effective at reducing corrosion, the use of such compositions must be carefully monitored as nitrite and nitrate salts are toxic. To reduce the hazard created by the presence of nitrite and/or nitrate salts, corrosion inhibitor compositions free of nitrite and nitrate salts have been created. One such nitrite and nitrate salt free corrosion inhibitor composition disclosed in U.S. Pat. No. 3,948,792 discloses an aqueous solution of an alkali metal silicate, an alkali metal borate and a polymeric dispersant. One drawback associated with this composition is the inability to form a highly concentrated corrosion inhibitor composition because of the low water solubility of silicates and borates. A concentrated form could reduce shipping and handling costs and reduce the storage area required.
Accordingly, a substantial need exists for a concentrated, nitrite and nitrate free, corrosion inhibitor composition which may be conveniently dispensed into an aqueous system.